BobCajun
Well-Known Member
3.2.7 Separation of acidic and neutral Cannabinoids
A glass-filter (mesh size 2) of about 5 cm in diameter and 7 cm in height was filled for 2/3 with
acid-washed sea-sand (Sigma) and topped with glass pearls (±1 mm diameter). Before use the sand was sequentially washed with 200 ml of hexane, ethanol and water. Cannabis hexane extract was concentrated to about 5 ml of hexane, placed drop-wise on top of the sandfilter and evaporated by using a warm air blower. The sandfilter was then placed onto a suction
Erlenmeyer and acidic cannabinoids were eluted by washing the sandfilter under vacuum with
a 0.1 M NaOH solution. The elution was continued until the eluate turned from deep-orange
to colorless. Neutral cannabinoids and other compounds were then eluted with ethanol (200
ml), followed by hexane (200 ml). Acidic cannabinoids were precipitated in the aqueous eluate
by adding HCl until the pH reached 2 and then filtered through the (dried) sandfilter. The
precipitate that remained on top of the sandfilter was finally eluted with ethanol (200 ml).
Neutral and acidic cannabinoid fractions were both concentrated into a small volume by
evaporation under reduced pressure and analyzed by GC and HPLC.
Arno Hazekamp
Cannabis; extracting the medicine
Proefschrift Universiteit Leiden
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